KEYS TO THE GAME: The Lions' improving ground game has been instrumental in the team becoming increasingly competitive. But with RB Kevin Smith dealing with a shoulder injury, Maurice Morris and rookie Aaron Brown might need to shoulder the load. Detroit must run the ball to help rookie QB Matthew Stafford avoid turnovers, and it has to stop the run defensively to help out its poor pass defense. Chicago has rushed the ball 75 times this season, but for just 2.8 yards per pop. QB Jay Cutler has improved his passer rating each game, however, and much of it is due to quick throws. The Lions' 30th-ranked pass defense must tackle well to prevent back-breaking plays after the catch.
FAST FACTS: Bears defensive line coach Rod Marinelli was the Lions' head coach from 2006-08. ... Cutler's teams are 12-0 when he has a passer rating of at least 100.
--DT Sammie Hill did not practice Wednesday and Thursday because of an ankle injury. Considering the Lions felt the need to sign veteran DT Chuck Darby, it seems unlikely Hill will play.
--S Kalvin Pearson did not practice Wednesday or Thursday because of a quad injury, though he did some running on the side Thursday. He seems unlikely to play.
--DE Dewayne White did not practice Wednesday or Thursday because of a hamstring injury. He seems unlikely to play.
--DE Cliff Avril was listed as limited in practice Wednesday and Thursday. He seems likely to return after missing two weeks with a hamstring injury.
--CB Eric King was listed as limited in practice Wednesday and Thursday. He seems likely to return after missing a game with a shoulder injury.
--LB Ernie Sims was listed as limited in practice Wednesday and Thursday. He seems likely to return after missing a game with a shoulder injury. He said he begged the coaches to let him play Sunday against Washington, but they held him out, snapping his streak of 50 straight starts.
--DT Grady Jackson was listed as limited Wednesday and did not practice Thursday. But that has been the routine for the 36-year-old veteran, who had knee surgery in the offseason.
--LB Lance Briggs (toe) was limited at practice Thursday but is expected to play Sunday.
--TE Desmond Clark (fractured rib) participated fully in practice but with the bye week coming up the Bears will probably be cautious and sit him for another week.
--LB Pisa Tinoisamoa (sprained knee) has not practiced all week and will not play Sunday but is expected back after the bye, when the Bears play the Falcons in Atlanta on Oct. 18.
--LB Hunter Hillenmeyer (ribs) did not practice and will probably not play on Sunday.
--LB Nick Roach will start somewhere on Sunday. If Hunter Hillenmeyer is out, Roach will be in the middle and Jamar Williams will be on the strong side. If Hillenmeyer plays, which is not expected, Roach will be on the strong side.
--LB Jamar Williams will start on the strong side Sunday if MLB Hunter Hillenmeyer does not play and Nick Roach has to move from the strong side to the middle.
INSIDE THE CAMPS
Running back Kevin Smith returned to practice Thursday, a sign that he might play Sunday at Chicago.
Smith left Sunday's game against Washington with a shoulder injury. His said Monday that his goal was to return to practice Wednesday, and he didn't practice Wednesday.
But Smith also said Monday that he needed at least two days of practice to feel prepared to play at a high level, and if he practices again Friday, he will reach that minimum.
Coach Jim Schwartz was coy. Asked if he was encouraged by Smith's progress, he said: "He practiced today." Asked if Smith is behind or ahead of schedule, he said: "He'd be behind a normal person who had never had their shoulder hurt."
Schwartz doesn't discuss injuries during the season because he doesn't want to give opponents a competitive advantage.
"We'll see on Sunday," Schwartz said. "There's still going to be a game-time decision, for sure. It's a lot different practicing than actually going through a game, but he's making progress."
If Smith can't play, there could be a big dropoff.
Smith was on his way to surpassing his career high of 112 rushing yards when he got hurt. He rushed for 101 yards on 16 carries against the Redskins.
Veteran Maurice Morris and rookie Aaron Brown have almost identical, unimpressive statistics. Both have 25 yards on 10 carries.
Morris rushed for only 10 yards on eight carries against the Redskins. But offensive coordinator Scott Linehan pointed out that Morris missed a significant portion of training camp with a hamstring injury.
"I think he's starting to get his legs," Linehan said. "He's been a guy that's been relied on before to carry the load, and that's another reason why he's here, because we know he can do it."
Listening to Linehan, it sounds like Smith will at least play some role Sunday, but the others will need to pick up some slack.
"You're going to have to have other guys carrying the ball through the course of the season, anyway," Linehan said. "But our plan is that we're going to have everybody available and play guys in certain situations.
"Until I'm told any different, we're certainly planning for other guys to be able to carry, because he did get himself banged-up a little bit. We'll wait and see. But the other guys are ready to go. ...
"We've got a plan for other guys playing, but I'd like to think that all of them are going to play a certain amount of time."
Bears assistant head coach/defensive line coach Rod Marinelli isn't the kind of man to get all maudlin just because his former team is coming to town, the one that compiled the only 0-16 record in NFL history last year with him as the head coach.
Marinelli and the Bears host the Lions Sunday at Soldier Field, and he said he wouldn't get emotional over it.
"For me? No way," Marinelli said. "I'm not built that way. All my energy is to our team. I just look at what we're doing. I'll be looking at us and see how we play and worry about our pad level and all the things that we have to do to execute well.
"I get wired in for our guys. Any thoughts that go any other place other than this team, that's wrong on my part."
Admitting only that "it was difficult," last season, Marinelli said he tried to take positives from the disaster.
"Adversity is something special; it really is, if you embrace it correctly," Marinelli said after Thursday's practice. "If you run from it, it'll wear you out. But if you embrace it and find a way to get better ... that's what I tried to do. That's (something) that you have a chance to really grow from. When you're hitting bumps, you become more creative. I became more determined, and you embrace the moment."
Fired by the Lions, Marinelli was quickly snatched up by Lovie Smith, who spent five years (1996-2000) as the linebackers coach in Tampa while Marinelli was in the midst of coaching the league's best pass-rushing defensive line. Despite their friendship, Smith said he didn't feel compelled to root for the Lions last season for Marinelli's sake.
"He's not looking for a whole lot of sympathy," Smith said. "You go through things that don't turn out the way you wanted them to sometimes and then you move on. Rod has done that. You saw the smile on his face. He's happy with where he is right now."
Marinelli dismissed the idea of his current players winning Sunday's game for him, and he hasn't made it an issue. But the Bears' defenders know what's up.
"He's the same guy, but let's be real," defensive end Adewale Ogunleye said. "I know this is a game that's going to be a little closer to his heart. He's going to want us to play well. And he's definitely going to want us to win the game. He's not showing his cards, but we're not dumb. We know what it means to him."